Degreasing composition useful for degreasing and/or decontaminating solid surfaces

Abstract

The invention relates to a degreasing composition in liquid, gel or foam form for degreasing and/or decontaminating solid surfaces. This composition comprises an aqueous solution of nitric acid including: at least one first, emulsifying non-ionic surfactant consisting of a polyethoxylated fatty alcohol, and at least one second, wetting non-ionic surfactant consisting of a copolymer of ethylene oxide and propylene oxide.

1 . Liquid degreasing composition comprising an aqueous solution of an inorganic acid, including: 
 at least one first, emulsifying non-ionic surfactant consisting of a polyethoxylated fatty alcohol, and    at least one second, wetting non-ionic surfactant consisting of a copolymer of ethylene oxide and propylene oxide.    
     
     
         2 . Composition according to  claim 1 , wherein the inorganic acid is nitric acid.  
     
     
         3 . Composition according to  claim 2 , wherein the nitric acid concentration of the aqueous solution is from 0.1 to 5 mol.L −1 .  
     
     
         4 . Composition according to any one of  claims 1  to  3 , wherein the total surfactant concentration is from 1 to 20 g.L −1 .  
     
     
         5 . Composition according to any one of  claims 1  to  4 , wherein the first, emulsifying surfactant is a polyethoxylated fatty alcohol of formula:  
       R 1 —(OCH 2 CH 2 ) n —OH  
       in which n is an integer ranging from 2 to 20 and R 1  is a saturated or unsaturated hydrocarbon chain having 9 to 18 carbon atoms.  
     
     
         6 . Composition according to  claim 5 , wherein n is an integer ranging from 6 to 15 and R 1  is an alkyl group of 11 to 13 carbon atoms.  
     
     
         7 . Composition according to any one of  claims 1  to  6 , wherein the copolymer of ethylene oxide and propylene oxide is a block copolymer containing from 1 to 8 ethylene oxide units and from 3 to 12 propylene oxide units.  
     
     
         8 . Composition according to any one of  claims 1  to  7 , wherein the mass ratio of the first, emulsifying surfactant(s) to the second, wetting surfactant(s) is from 2 to 10, preferably around 4.  
     
     
         9 . Composition according to claims  6  and  7 , containing 8 g.L −1  of the first, emulsifying surfactant and 2 g.L −1  of the second, wetting surfactant.  
     
     
         10 . Composition according to any one of  claims 1  to  9 , further comprising a third surfactant consisting of a phosphoric ester.  
     
     
         11 . Composition according to  claim 10 , wherein the phosphoric ester is of the formula: C 5 H 17 OOP(OR 2 ) in which R 2  is a hydrocarbon group of 4 to 10 carbon atoms.  
     
     
         12 . Composition according to either of claims  10  and  11 , wherein the concentration of the third surfactant is from 0.1 to 3 g.L −1 , preferably 0.5 g.L −1 .  
     
     
         13 . Composition according to any one of  claims 1  to  9 , further comprising from 0 to 0.5 g.L −1  of tributyl phosphate as antifoam.  
     
     
         14 . Degreasing foam comprising a gas phase and a composition according to any one of  claims 1  to  13 .  
     
     
         15 . Foam according to  claim 14 , further comprising one or more additives.  
     
     
         16 . Degreasing gel comprising a degreasing composition according to any one of  claims 1  to  13  and an inorganic viscosity enhancer.  
     
     
         17 . Gel according to  claim 16 , wherein the viscosity enhancer is alumina or silica.  
     
     
         18 . Method of degreasing and/or decontaminating a surface, which comprises contacting the surface with a composition according to any one of  claims 1  to  13  in order to extract the products contaminating this surface into this composition.  
     
     
         19 . Method of degreasing and/or decontaminating a surface, which comprises contacting the surface with a foam according to either of claims  14  and  15  in order to extract the products contaminating this surface into this foam.  
     
     
         20 . Method of degreasing and/or decontaminating a surface, which comprises contacting the surface with a gel according to either of claims  16  and  17  in order to extract the products contaminating this surface into this foam.  
     
     
         21 . Method according to any one of  claims 18  to  20 , wherein the products contaminating the surface are one or more of the following products: tributyl phosphate (TBP), dibutylphosphoric acid (HDBP), monobutylphosphoric acid (H 2 MBP) and their salts and complexes with uranium, plutonium and radioactive metals, and the oxides and nitrates of uranium and of plutonium.